Paper edge transport system

ABSTRACT

Improved sheet material handling apparatus and method having two rotating belt members disposed at opposite edges of the sheet for engaging or gripping the sheet between the belts by application of a slight compressive force. Pressure means such as a pair of plates are disposed adjacent the sheet material to confine the sheet material and prevent buckling of the sheet material.

lite States Patent H 1 Thiel .lan.8,1974

1 1 PAPER EDGE TRANSPORT SYSTEM [75] Inventor: John A. Thiel, Wheeling, Ill.

[73] Assignee: Bell & Howell Company, Chicago,

Ill.

[22] Filed: Mar. 30, 1972 [21] Appl. N0.: 239,476

[52] U.S. Cl 271/45, 198/165, 226/172 [51] Int. Cl B65h 5/02 [58] Field of Search 271/45, 49, 75, 76, 271/68; 226/172; 198/180, 179, 165;

[56] References Cited UNITED STATES PATENTS 3,651,961 3/1972 Hayes .1 271/68 X 3,136,209 6/1964 Briskin et al 352/224 X Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. AttorneyJames M. Wetzel et a1.

[ 5 7] ABSTRACT Improved sheet material handling apparatus and method having two rotating belt members disposed at opposite edges of the sheet for engaging or gripping the sheet between the belts by application of a slight compressive force. Pressure means such as a pair of plates are disposed adjacent the sheet material to confine the sheet material and prevent-buckling of the sheet material.

8 Claims, 3 Drawing Figures PAPER EDGE TRANSPORT SYSTEM This invention relates to sheet material handling, and more particularly to a method and apparatus for conveying a piece of sheet material between a first position and a second position in a device wherein the sheet material is exposed to a reproduction process in one position and developed in the other position.

This invention finds advantageous employment in effecting the rapid and efficient movement of sheet material in a device where it is necessary to convey the sheet from one station to another. The conveying apparatus and method of the present invention may be adapted to move or convey sheet material in either a horizontal or vertical mode, since the means and method of the pres ent invention render the conveying apparatus relatively gravity insensitive.

The present invention is particularly adaptable for use in conjunction with a reader/printer where a photosensitive, pre-cut paper is first exposed to an image while held in a stationary mode, and then is conveyed to a second station for development. Present paper handling methods and apparatus use mating rollers to move the paper, with either a back-up roller or gravity system providing pressure for the conveying drive. In such systems, only a small portion of the paper; i.e., that portion which is in contact with the tangential surfaces of the mating rollers, is gripped by the conveying means. The small gripping surface thus afforded in prior systems results in only a small amount of conveying pressure, thereby resulting in a high degree of slippage.

Previous devices and methods for sheet material or paper transport comprise mechanisms using rotating belts positioned at opposite edges of the sheet being transported. In these methods and apparatus, the paper is not suspended between the edges of the belts, but instead is supported upon the flat surfaces of the belts by the force of gravity, or by the force of a roller or other suitable pressure means. Other prior art devices teach a document transporting device whereby the document is gripped between a stationary guide member and the outer surface of at least one moving transport member. Still other paper transporting means use rotating belts comprising knobs protruding therefrom for engagement with perforations in the paper to be transported. In none of the prior art devices referred to above is the paper transported by a means or apparatus which engages the edges of the sheet material and applies a compressive force for gripping the sheet.

Therefore, it is a primary object of the present invention to provide an apparatus and method for conveying sheet material whereby positive means grip the sheet and provide a slip-resistant surface for engaging the sheet material.

An additional object of the present invention is to provide a means and method for engaging the edges of sheet material between a gripping means for conveying the sheet material from one station to another.

Still another object of the present invention is to provide a means and apparatus for conveying material in the form of sheets between gripping means, including means to confine the material against buckling as a compressive force is applied to the edges of the sheet material by the gripping means.

Still an additional object of the present invention is to provide for use in conjunction with a photographic reader/printer apparatus, a means and method for conveying a photographic sensitive paper from a first station for exposure to a second station for developing by means of a positive edge gripping paper conveying means.

An additional object of the present invention is to provide for use in conjunction with a photographic reader/printer apparatus, a method and apparatus for conveying paper for exposure and development from one station to a second station between transparent screen plates forming part of the photographic reader/printer.

Still another object of the present invention is to provide material gripping means having a cross-section which enhances the ability of the gripping means to engage the edges of sheet material for movement from one station to a second.

The foregoing and other objects, features, and advantages of the invention will be apparent from the following detailed description of a preferred embodiment of the invention, as illustrated in the accompanying drawing, wherein:

FIG. 1 is a top view ofa document conveying apparatus employing the means and method of the present invention;

FIG. 2 is a side elevation view of the apparatus of FIG. 1; and

FIG. 3 is a section view taken along the lines 3-3 of FIG. 1.

Referring to FIGS. 1 and 2, a material conveying apparatus constructed in accordance with the present invention is designated by the numeral 10. The apparatus 10 consists of a pair of pulley axles l2 and 14 spaced apart at opposite ends of a pair of transparent plates 16, 18 (FIG. 2) which are the surface plates of a photographic reader/printer apparatus. Transparent plates l6, 18 are disposed parallel to each other a short distance apart, whereby a sheet material, such as a photoconductive sheet 20, may pass between the plates, moving from pulley axle 14 toward the direction of pulley axle 12. The arrow designated 21 in FIG. 2 denotes the direction of movement of sheet 20 between pressure means, such as plates 16, 18, as will be described. A photographic lens or the like (not shown) is disposed below plate 18 to project an image to be reproduced through the plate and onto photoconductive sheet 20.

With reference to FIG. 1, pulleys 22 and 24 are rigidly affixed at opposite ends of the axle 12. Likewise, pulley axle 14 comprises pulleys 26 and 28 rigidly affixed at opposite ends thereof. The present invention contemplates the use of a pair of rotating endless flexible belt members for gripping opposite edges of document 20. To this end, an endless belt 30 extends between pulleys 24 and 28, while a second endless belt member 32 extends between pulleys 22 and 26. As seen in FIG. 1, endless belt members 30 and 32 are disposed along plates 16, 18, and extend in a parallel direction along the edges of the plates. Pulleys 22, 24, 26 and 28 maintain belts 32 and 30 in a spaced relation such that the distance between the belts is slightly greater than the width of the plates 16 and 18, whereby the plates will not interfere with the rotation of belts 30 and 32. A nominal clearance of 0.010 inches is maintained between the edges of plates 16, 18 and the rotating belts for optimum efficiency of the invention.

Referring to FIG. 3, it will be seen that in the preferred embodiment, the belts 30 and 32 in cross-section are rectangular or square. Each belt comprises gripping means consisting of inner vertically extending face 34, 36 which is adapted to engage the edges of document 20, as shown in FIG. 3. The dimensions of the apparatus are such that the distance between vertical face 34 and vertical face 36 of belts 30, 32, respectively, are equal to the width of document passing through the apparatus, less 0.02 inches, nominally, for applying a slight gripping force, as will be explained.

In operation, the apparatus 10 functions as follows: The plates 16 and 18 form part of a photographic reader/printer apparatus where it is desired to expose one surface of sheet 20 to a photographic image while holding it in a stationary position, and then moving sheet 20 to a second position for development. In this regard, plates 16 and 18 are transparent to allow an image to be cast upon sheet 20 through plate 18 by means of photographic equipment, not shown.

In the present apparatus, a sheet 20 is fed or otherwise placed between plates 16 and 18. As best seen in FIG. 3, the vertically extending edges 34 and 36 of the rectangular or square belts and 32 grip the sheet 20 along opposite edges thereof. As indicated previously, the distance between faces 34 and 36 is slightly less than the width of the sheet held therebetween. Vertical faces 34 and 36 of the rotating belts impart a compressive force to the sheet 20, which grips the paper between belts 30 and 32.

As the belts 30, 32 rotate in the direction of arrows 21, 38 (FIG. 2), sheet 20 is moved in the direction of arrow 21. The sheet 20 is confined between plates 16, 18, which confer sufficient rigidity to the sheet to resist buckling due to the compressive force in the paper resulting from being gripped by belts 30 and 32. By holding the paper in this manner along its edges, apparatus 10 allows complete control of the sheet 20 in all modes of operation, and even allows the sheet 20 to be conveyed vertically since the sheet is gripped along the entire length of two of its four edges. As such, it is apparent that the present method and apparatus of conveying a piece of sheet material may be relatively gravity insensitive.

To impart movement to sheet 20, a driving force is imparted to either axle shaft 12 or 14 to rotate pulleys 22, 24, 26 and 28. This causes belt 30 and 32 to rotate, as indicated by the arrows 21, 38 in FIG. 2. As the belts 30, 32 rotate with sheet 20 held securely by faces 34 and 36 of said belts, the document is transported past plates 16 and 18 to a second position for development purposes.

For purposes of illustration, belts 30 and 32 are shown in rectangular or square cross-section. However, it must be understood that any configuration of belts 30, 32 may be utilized within the scope of the present invention which allows the belts 30 and 32 to engage the edges of a sheet material such as document 20. It is also apparent that other pressure means may be substituted for plate 16 or plate 18 to prevent the sheet material from buckling under the compressive force applied when gripped by belts 30, 32. In this regard, the plate which is disposed away from the photographic equipment used in association with apparatus may be replaced by pressure devices such as horizontally extending spring fingers to hold the sheet 20 from buckling under the force of the compression applied by belts 30 and 32.

While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention, which is defined by the following claims.

We claim:

1. Apparatus for conveying material in the form of sheets comprising:

a pair of rotating endless belt members disposed at opposite edges of said material, said belt members having surfaces defining planes generally parallel to the plane defined by the path of movement of said material;

gripping means defined by opposed facing edges of said belt members adapted to engage only the opposite edges of said material between said belt members and to apply a relatively slight compressive force to said material for conveying said material in the direction of movement of said gripping means; and

pressure means including substantially transparent plates disposed adjacent the surfaces of said material, said plates occupying less than all of the space between said opposed facing edges of said belts and being adapted to confine said material against buckling as said compressive force is applied by said gripping means.

2. The apparatus of claim 1 wherein said pressure means includes a pair of parallel transparent plates disposed adjacent either surface of said material, said plates having a transverse dimension less than that of said material so as to avoid contact with said opposed facing edges of said belts.

3. The apparatus of claim 1 wherein said endless belt members are relatively rectangular in cross-section, whereby said opposed facing edges comprises the vertical extending opposed-facing surfaces of said belt members.

4. The apparatus of claim 1 wherein the distance between said opposed facing edges of said belt members is approximately 0.02 inches less than the width of said sheet material engaged between said belt members.

5. The method of conveying material in the form of sheets comprising the steps of:

engaging the edges of said material between opposed facing edges of a pair of rotating endless belt members to effect the application of a relatively slight compressive force to said material as said material is conveyed, and

applying pressure to the opposite surfaces of said material while said material is being conveyed to prevent buckling of said material.

6. The method of claim 5 wherein said material is conveyed in a generally longitudinal direction responsive to rotational movement of said belt members.

7. The method of claim 5 wherein said material is conveyed between transparent plate means which apply pressure to opposite surface of said material while said material is being conveyed to prevent buckling thereof.

8. The method of claim 5 wherein the application of said compressive force is effected by arranging said belt members in spaced apart relationship separated by a distance of approximately 0.02 inches less than the width of said sheet material. 

1. Apparatus for conveying material in the form of sheets comprising: a pair of rotating endless belt members disposed at opposite edges of said material, said belt members having surfaces defining planes generally parallel to the plane defined by the path of movement of said material; gripping means defined by opposed facing edges of said belt members adapted to engage only the opposite edges of said material between said belt members and to apply a relatively slight compressive force to said material for conveying said material in the direction of movement of said gripping means; and pressure means including substantially transparent plates disposed adjacent the surfaces of said material, said plates occupying less than all of the space between said opposed facing edges of said belts and being adapted to confine said material against buckling as said compressive force is applied by said gripping means.
 2. The apparatus of claim 1 wherein said pressure means includes a pair of parallel transparent plates disposed adjacent either surface of said material, said plates having a transverse dimension less than that of said material so as to avoid contact with said opposed facing edges of said belts.
 3. The apparatus of claim 1 wherein said endless belt members are relatively rectangular in cross-section, whereby said opposed facing edges comprises the vertical extending opposed-facing surfaces of said belt members.
 4. The apparatus of claim 1 wherein the distance between said opposed facing edges of said belt members is approximately 0.02 inches less than the width of said sheet material engaged between said belt members.
 5. The method of conveying material in the form of sheets comprising the steps of: engaging the edges of said material between opposed facing edges of a pair of rotating endless belt members to effect the application of a relatively slight compressive force to said material as said material is conveyed, and applying pressure to the opposite surfaces of said material while said material is being conveyed to prevent buckling of said material.
 6. The method of claim 5 wherein said material is conveyed in a generally longitudinal direction responsive to rotational movement of said belt members.
 7. The method of claim 5 wherein said material is conveyed between transparent plate means which apply pressure to opposite surface of said material while said material is being conveyed to prevent buckling thereof.
 8. The method of claim 5 wherein the application of said compressive force is effected by arranging said belt members in spaced apart relationship separated by a distance of approximately 0.02 inches less than the width of said sheet material. 